Clip for holding detonators in blasting cartridges



July 1, 1947. F. H. ROLFES 2,423,255

CLIP FOR HOLDING DETONATORS IN BLASTING CARTRIDGES Filed June 29, 1945 Patented July 1, 1947 V UNITED s'm'ra CLIP FOR HOLDING ,DETONATORS IN BLASTING CARTRIDGES.

Fritz Hermann Rolfes', Johannesburg, Transvaal,

IUnion of South Africa Application June 29, 1943, Serial No. 492,740

1 Claim.

1 This invention, relates to clips for holding detonators in blasting cartridges of the type in which the clip isadapted to'have one of its ends .or parts (hereinafter termed the attachment .part) attached. to a portion of the detonator orits fuze r (in the case of an electric detoladetonator in a blastin cartridge comprises an attachment part having an opening adapted to be brought alongside the portion of the detonator or its fuze or cable on which the clip is to be received and a hook element which is continuous with the said opening and. adapted to ,be movedtransversely to the said clip.-receiving portion and to abut against. either the end of the detonator or a shoulder or other projecting portion and thereby lock the clip in place, and means adapted to be pressed into the cartridge to hold the detonator therein.

The clip in each case is preferably made in a single piece from copper wire or other nonspark-producing material.

Several clips embodying the invention will now be described with reference to the annexed drawing, in which- Figs. 1 to 5 are perspective views of various hook-on clips according to the invention, made of wire of copper or other non-spark-producing metal.

Figs. 6 and 7 are perspective views of further hook-on Wire clips according to the invention.

Referring to the drawings, it will be seen that the clips shown are made of wire, the wire being of copper or other non-spark producing material. In Fig. 1, the clip is constituted of a piece of wire doubled upon itself so as to constitute a keyhole part l8, and a prong l9 having an inwardly bent claw 20. If desired, the two ends of the wire which constitute the point of the claw may be fixed together, e. g., by solder, Welding or hammering.- In Fig. 2, the clip is likewise constituted of a copper or equivalent wire doubled upon itself so as to constitute, firstly, an attachment part having an inner loop 2| united by a constricted neck 22 to a bifurcated entrant portion 23, and secondly, a prong 24 which con- 2 sists of spaced parallel lengths 25, 25 of the wire which are bent inwardly and conver e to a point 2'! so as to constitute the claw 28 of the clip. Preferably, the ends of the wireare soldered, or otherwise secured together so to form aV-shaped (or alternatively a Y-shaped) point 21,. ,andthe 1engths'25, 26 of the wire may be crossed or twisted together. In Fig. 3, the clip consists of a piece. of wire 29 bent at the bottom so as tov constitute an inwardly directed claw 30 and a hook 3| at the top, this hook being of lobate shape so as to provide an inner loop 3i and a larger outer loop 32, united together by a neck. portion33. In "Fig. 4, the clip is similar to that described with reference to Fig. 3 and the same references denote similar parts. The clip shown inFig. 4, however, has ahook consisting only of an inner loop 3H and a constricted neck 33. "Il'LFig. 5, the clip is of the same general construction as thatshown in Fig.

2 and similarreference' numerals in thesetwo figures denote similar parts. The clip shown in Fig. 5, however, has theouter bifurcated parts 23 0f the attachment piece made divergent, whilst the ends of the wire at the eXt-remitybf the claw 28 are bent round upon themselves so as to form barbs 34, 35.

The wire clips above described with reference to Figs. 1 to 5 all have the inner portion or loop of their attachment part made of a size adapted to fit or be sprung on to the fuze or cable of the detonator, or a groove or equivalent thereon, and the length of the prong is made in each case sufficient for the claw to be situated below the end of the detonator when the clip has been attached in position, the detonator inserted in the cartridge, and the point or claw of the prong pressed into the side of the cartridge. As will be appreciated, the manufacture of clips out of wire as just described is very economical, and it has been found that these clips are entirely satisfactory for the purpose in view.

The attachment part and claw of the wire clips shown in Figs. 1 to 7 are preferably bent at a slight upward angle with respect to the vertical portion or prong of the clip, it having been found that this formation improves the efifectiveness of the attachment of the clip to the fuze or detonator and the grip of the clip upon. the cartridge.

As will be understood, the provision of a constricted neck in the hooks or slots of the clips, as illustrated, furnishes a safeguard against the clips becoming accidentally removed from off the fuze or detonator.

The clip shown in Figure 6 comprises an attachment part 2|, 22, 23 similar to that already described with reference to Figure 5. The parallel lengths 25, 26 of the wire, however, are spaced more widely apart, viz., a distance materially greater than the diameter of the detonator. The clip is formed with inwardly bent prongs or claws 4|, 42 and in practice, may be fitted to the cartridge by means of these claws, so that the attachment part 2|, 22, 23 lies upon the top of the cartridge with the inner loop 2| over the hole which is pierced in the said top to receive the detonator. The latter is inserted into the hole, either by moving aside the attachment part temporarily from the hole or by easing apart the sides of the loop 2|.

The clip shown in Figure 7 has a hook or loop 43 with constricted mouth 44, and its bifurcated parts 45, 46 extend outwards in opposite directions, so that the vertical portions 41, 48 and fiattened claws 49, 50 can be engaged with the opposite sides of the cartridge to which the clip is to be fitted.

In both the clip shown in Fig. 6, and that shown in Fig. 7, the prongs or claws may be made shorter (as illustrated) than the length of the detonator to be inserted in the cartridge, there being no danger of the prongs or claws being thrust into the detonator, which simply lies (within the cartridge) between the prongs or claws.

. In the caseof any of the wire clips shown, the hook or loop portion, adapted to be passed on to the fuze or cable, may (in virtue of its flexibility) be compressed together after it has been fitted in place, so as to embrace the fuze or cable firmly and ensure effective abutment against the end of the detonator.

If desired, the points or claws of the wire clips may be flattened in the plane normal to the direction in which an outward pull upon the clip parallel to the axis of the cartridge would act, so as to increase the gripping area of the claws onthe wrapping and explosive material of the cartridge.

In the appended claim, the term projecting portion of the detonator is used to denote either the end of the detonator casing from which the fuze or electric cable extends, or a shoulder or similar surface provided by a groove, notches or the like on the said casing, and the term clipreceiving portion of the detonator denotes the fuze, cable or other part (adjacent to the projecting portion of the detonator) on which the clip is fitted.

I claim:

A detonator clip including a single length of wire bent substantially centrally of that length to form an eye to embrace the fuse immediately beyond the detonator, then reduced in diameter to provide a restricted neck, then projected laterally in the plane of the eye, and downwardly to overlie the detonator, the lateral portions being formed in spaced strands, the terminals of the strands remote from the eye being bent laterally and terminally arranged to provide a piercing point to enter a cartridge, the spaced strands of the part overlying the detonator providing a means whereby the diameter of the neck may be reduced by movingv the stnands toward one another to insure more secure fixing of the clip in position on the fuse.

FRITZ HERMANN ROLFES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 468,890 McFarland Feb. 16, 1892 2,318,282 Bjorkman May 4, 1943 FOREIGN PATENTS Number Country Date 733,254 France July 4, 1932 107,595 Australia June 15, 1939 532,285 France Nov. 10, 1921 

